This invention relates to water-cooled furnace systems, e.g. electric arc furnace systems and more particularly to slag retaining means in the form of an elongate metal insert extending from inside the furnace vessel through the wall of a water-cooled furnace wall section and into the water contained therein.
Spray cooled electric furnace systems of the type disclosed in U.S. Pat. Nos. 4,715,042, 4,815,096 and 4,849,987 involve the spray cooling of furnace closure elements, e.g. roofs and side walls, which are unitary, i.e. formed into one piece, and have a generally cylindrical or oval in the case of a furnace side wall or other closure element. Due to the geometry of furnace electrodes and oxygen lances, variations in heating of the furnace, and the like, regions of the surface of a spray cooled closure element can be exposed to unusually high temperature and become thermally stressed with the risk of failure at such regions.
A furnace system as above described is typically made of steel, aluminum, aluminum base alloys, copper, copper base alloys and metals having similar thermal characteristics and have metal slag retainers, made from the aforesaid metals attached to the furnace side of the metal closure elements. These slag retainers, typically cup-shaped to aid in slag retention being unprotected from the high furnace temperatures, have a relatively short life due to overheating and oxidation. The use of the more oxidation resistant and thermally conductive materials in the slag retainers would result in substantially higher cost without commensurate benefit.
It is therefore an object of the present invention to provide improved slag retainers for a water-cooled furnace closure element with enhanced slag retention to reduce damaging heat.